All Activity

To explain it really simple. If you have a ground rod on one end of your house for your service and another one at the other end of the house with your radio gear and they are not bonded together. If you have a strike, even a ground strike at one end of the house, a tree near the house, or whatever at that end. The lightning will COME IN the one ground, go through your equipment via the safety ground (bottom pin on power cord) across the equipment / power supply, into the radio then back out to the coax or ground wire, then out to the ground rod it's all hooked to. That is the difference of potential that is talked about. The ground is NOT a perfect conductor. And it's not unreasonable to see 50 Kv or more across 10 feet of ground during a strike. I install public safety radio sites, including ones that are co-located dispatch centers with radio towers. Key part of this is the dispatchers wear headsets that as far as lightning goes, a direct path exists between the top of that tower and their headsets. You BOND everything. The headset jack gets bonded, the furniture, the equipment, the racks the equipment is in, the radios, the wiring between the radios and the console electronics, the coaxes entering the building with a surge suppressor, then outside the building, at the base of the tower, every 100 foot up the tower and then right at the connection point to the antenna. The tower gets bonded to all this. Then there are ground rods on every leg of the tower. Those are bonded together, called a tower ground loop. Then the building has a ring around it with ground rods every ten feet again in a loop. Those rings are bonded together, there are lines that go out into the property with more ground rods that are every 10 feet. All the connections are done with CadWeld or 15 ton compression connections with a hydraulic press. All that is bonded to the service entrance ground. Then in the building, everything that is metal that is a fixture gets grounded. Meaning file cabinets, conduits, desks, window and door frames. Anything that not immediately movable. Of course, air handlers, plumbing, and the like are also bonded back to the ground along with the building frame if it's conductive. A lot of people will question the required wire gauge, stating that a number 2 wire could never hold the current of a direct strike. And that's only partly true. Lightning is very fast. Wire will carry a very high amount of current for a very short amount of time. Anyone that's ever shorted something across a battery will recognize that whatever it was didn't instantly turn to plasma and vanish. It takes some time for the wire to heat up and then catch fire. And longer for it to burn in half. It's that fact that allows a number 2 conductor to take the abuse of being hit across and not just being vaporized. Yes, there are instances that heavier wire is needed. Like the ground rings, runs longer than 50 feet and situations where a multipoint grounding bar is located where a number of devices are connected to a single point with number 6 wires. But a number 6 wire, at least with the R56 install standard, is the minimum required wire gauge for any ground and if it's connected to a ground bar with other devices or grounded objects, then the wire going from that ground bar back the the master / main ground bar needs to be a number 2.

It still appears in the database, but browsing the map it doesn’t appear. I don’t know why. I tried it with offline and stale both turned on.

Vary Strong 462.7000 Using a Tone of DPL 351 in and around Monco and Philadelphia area. I normally use it but no one seems to answer depending on 822 Anthony answers you back .

You are the opposite of a “Sad Ham”. Great job!

I just came back from our club's Field Day exercise. I spent about an hour as a control operator with an unlicensed operator, showing him how to make contacts and a little bit on how to operate the radio (tuning, notch filtering, RF gain vs AF volume). He had 22 contacts on 40 meter phone (7.2-7.3 mHz) when I turned him over to another licensed operator, most across the country and a couple in Canada. He was very excited and was having a great time.

I programed my AR-10 today.. Its dead center in tune.

Obviously you don’t ground a fiberglass mast, but your coax shield is attached to part of the antenna somewhere and it will develop a charge as air currents pass over it. Now the difference in potentials is between the metal parts of the antenna connected to the shield of the coax and the service ground, again going through your equipment and possibly you. One of the purposes of a surge suppressor (commonly called a lightning protector but nobody guarantees that) is to allow you to bond the coax shield to the grounding system.

It's no different than using a chimney mount or a satellite dish mount on your roof. You run the proper sized ground wire from the antenna/mount to ground. Look at a properly installed satellite dish antenna. There will be a ground wire running with the coax. And that ground wire should be bonded to your service ground before the coax enters the structure. The same goes for cable TV, there will be a ground wire coming off the feed to your home and it to will be grounded to the service ground when installed correctly.

How does it change the calculations if the antenna is mounted on something non-conductive like a fiberglass mast?

Use one of the many coax loss calculators to see if the loss for that length is acceptable to you.

Dogs like us struggle with keyboards. I'm trying to get into CW. Strait key obviously. Paddles are out of the question.

Unless I misread the NEC and other sources, the tower should have its own ground and be bonded to the service ground. This is correct. Steve did a good job of expelling things

Let’s disregard lightning protection for a few minutes and just talk about bonding to your house service ground. Your tower is sort of grounded. We all agree with that I think. It’s embedded in an imperfect conductor, concrete, at the bottom. To improve the grounding a ground wire runs from each leg of the tower to a ground rod. But any two separate ground rods are almost always at different potentials. Whenever you have different potentials between two points in a circuit you will have electric currents flowing from one point to the other. So, the three or four legs of the tower are bonded together using a material that is more conductive than the tower itself. Otherwise you have current flowing between the legs of your tower. If current flows between the legs of your tower over time the metal of the tower will corrode. Bonding between the three or four legs provides an easier path for the current to flow which keeps the legs all at the same potential. In addition your antenna mount is certainly connected electrically to your tower and your coax shield is connected to your antenna mount. Your coax shield then runs to your radio. If you have a watt meter, amplifier, or any other device between your radio and your antenna, they are all connected serially via the coax shield. Their metal cases are all connected to the coax shield. So all of the devices in your shack are connected together via the coax shield. If a power surge comes through the shield (static, lightning, unicorn farts, whatever) it is going to cause current to flow through your equipment because that’s the most direct path. By bonding the chassis of all those devices to a single point, we provide a much better path that doesn’t flow through those devices. So that’s why we use a single point ground. But remember, that single point ground is connected to ground at the tower. You power your radio with a power supply that’s plugged into your house power. Its case is connected to the ground wire in the outlet which runs back to the service panel where it’s bonded to the service ground for the utility power coming into your house. It has to be because NEC says so. So let’s say you don’t have your single point ground bonded to your service ground. You reach out to touch your radio and at the same time your brush your other hand on the power supply. The potential of your tower ground, which is what your one hand is touching, is probably different than the potential of the service ground, which is what your other hand is feeling. And it’s DC. Your heart can be stopped by as little as 1/10 of an ampere. So you die. So we bond the tower ground to the utility ground to ensure they are at the same potential and save your life. Also with fewer ground currents in the shack we hear less noise.

What happened to the Winslow repeater in NW Arkansas? It doesn't come up on the gmrs map and it does not seem to work for me anymore.

I’m thinking I’m going to build a repeater. I’m making a shopping list. I want to use two Kenwood tk-8180 radios and a mobile Celwave 633-6a-2 duplexer. I keep seeing images of people using what looks like rg400 coax from the radios to the duplexer. I used lmr400uf ultra flex from DX Engineering to connect my base station and I have some left over. But the lmr400uf is still stiff for such a small distance from radio to duplexer. If I use a smaller coax like the rg400 vs the lmr400uf will it make that much of a difference? thank you!

So, a home antenna tower shouldn't have it's own ground? Just bond to house ground?

I'm not following you. What does that have to do with lightning protection? What kinds of problems will it cause? To be clear, I'm not being confrontational. I'm really trying to understand this.

To prevent electrical noise being transferred from one system into the other system. You are drawing power from one electrical system thus you should be using only one grounding system. If you have two earth grounding points then you have two grounding systems and that will cause problems.

Today, after much research, I programmed my new AR-152 radio using Chirp. I used the UV5-XP profile because it was recommended in another forum, is similar to what the manufacturer recommends, and features three power-level settings. After downloading and saving the factory settings, I uploaded my list of frequencies to the AR-152 using the UV5XP profile. I did not mess with frequency range or any advanced settings. So far I have only modified a few basic settings like muting the beep and voice. As measured by the Farsometer, the transmit power levels remained the same before and after programming with Chirp. I am still testing, but so far the radio appears to function as designed. Pre-Chirp: Freq. 155.500 H: 8.2 watts, M: 6.3 watts, L: 2.08 watts Freq. 438.500 H: 9.2 watts, M: 5.8 watts, L: 2.4 watts After Chirp: Freq. 155.500 H: 8.2 watts, M: 6.3 watts, L: 2.15 watts Freq. 438.500 H: 9.3 watts, M: 5.9 watts, L: 2.5 watts

Correct - Because Commercial Sites Don't Have A House - They Have A Structure Or A Cabinet For Equipment. The Structure Or Cabinet Requires Proper Bonding - For Single Point Grounding - To Avoid A Ground Potential Difference.

Hello Group! Here is a quick repeater system update! 6/28/25 SGA-575 is on the air! New updated repeater is in and being readied to be installed in the near future. Also antenna crew is being scheduled to replace the existing antenna with one that has higher gain. SGA-600 is on the air! Intermittent noise issues....Replacement duplexers have been received and tuned. Scheduling date to install them. SGA-650 is NOT on the air! Down due to hurricane Helene tower being destroyed. New site has been located and equipment is being ordered. Tower crew to be scheduled for work. No ETA at this time. SGA-700 is on the air! No issues noted at this time. Thanks, Scott Haner - SYSOP WRFS362

That was my logic, hence my confusion at the recommendation to do that.

Yes, but commercial tower sites don't then bond the ground to a house ground. What I'm trying to figure out is why almost every article or video I find recommends doing that.

The actual ground (i.e., dirt) can be a conductor of lightning that hits nearby, especially wet ground in a thunderstorm. By installing grounding wires, you may be increasing potential of that getting to your electronic devices inside. For ordinary folks, disconnecting the devices from the AC and antenna lines is the best option.

It's Called Single Point Grounding. Reason - To Eliminate A Potential Difference Between Having (2) Separate Grounding Systems. Single Point Grounding Is Done On All Commercial Tower Sites.